Climbing out of EloHell as a jungler

Hey guys. I've been fairly new to the ranked system, I have been on league since early season 5 and after achieving over 250 normal wins as a jungle main I have finally decided that am now ready to face the ranked season and have now been trying my hardest to climb the ladder out of bronze. At first I thought I could climb by becoming a support main because I was too shy and nervous to carry by myself, but I realized that without a good adc your pretty much useless unless you can go full AP. So I then decided to start maiming midlane with yasuo, zed, akali, and other assasin-like champions but am often annoyed of no many how many times I try to set a good gank for my jungler they never really come and do it unsuccessfully. I know switching roles and mains a lot may be bad but I want to try and help carry my team as much as possible and becoming a jungler again will help with the ability to roam around the map as much as possible to help all of my team mates but the only problem is that I am not sure which champion to choose anymore and that is where I need your help. As a normals player, I use to play Warwick jungler because he was just so easy and now in ranked I've discovered it's very easy to steal and counter jungle him. I only have a limited amount of IP and I want to buy a good jungler champion to play with but I'm not sure which one to get, should it be ashy Ana with her amazing wave clearance, hecarim with his great movement speed, tankiness and armor penetration, or kha'zix with the ability to become invisible and gank lanes easily. Please post your sugestione below it will be greatly appreciated and thank you for your help!